CAJ | 학술논문

通过实验与数值模拟对比验证了k-ε湍流模型用于模拟圆管突扩流场的可行性。对处于湍流水力光滑区（4000＜ Re＜105）的8组 Re流态下，突扩比为2．0、2．5、3．0、3．5、4．0、5．0的工况分别进行数值模拟。研究结果表明数值模拟计算得到的局部阻力系数小于传统理论公式局部阻力系数，两者差距随 Re的增大而减小。分析得知该结果是由于局部阻力系数传统计算公式未考虑沿程水力损失所造成，沿程水力损失随 Re的增加而降低，因此数值实验结果与理论公式计算结果会随 Re的增大而减小，传统计算公式在小 Re的工况下误差高达14％。
통과실험여수치모의대비험증료k-ε단류모형용우모의원관돌확류장적가행성。대처우단류수력광활구（4000＜ Re＜105）적8조 Re류태하，돌확비위2．0、2．5、3．0、3．5、4．0、5．0적공황분별진행수치모의。연구결과표명수치모의계산득도적국부조력계수소우전통이론공식국부조력계수，량자차거수 Re적증대이감소。분석득지해결과시유우국부조력계수전통계산공식미고필연정수력손실소조성，연정수력손실수 Re적증가이강저，인차수치실험결과여이론공식계산결과회수 Re적증대이감소，전통계산공식재소 Re적공황하오차고체14％。
By comparing the experimental and numerical simulation ,we verify that the k-εturbulence model can be used to simulate the flow field of sudden enlargement in circular pipes and extended working conditions .Numerical simulation experiments are con‐ducted in the turbulent smooth areas (4 000< Re<105) of 8 groups of Reynolds number flow state ,with the sudden expansion ratios 2 .0 ,2 .5 ,3 .0 ,3 .5 ,4 .0 ,5 .0 .The results show that the local loss coefficient value obtained experimentally is less than the calculated value through traditional theory .The gap between the two cases decreases with the increase in Reynolds number .An analysis shows that the results are due to the traditional formula of local loss coefficient ignored hydraulic losses along the tube .Frictional head loss decreases with the increase in Reynolds number .So the gap between the numerical results and calculated values decreases with the increase in Reynolds number .The deviation of traditional calculation causes conditions of low Reynolds number to reach 14% .